Hypodiploidy in AML.

Objectives: Acute myeloid leukemia (AML) is a heterogeneous malignancy of precursor myeloid cells. Identification and understanding of chromosomal abnormalities are key diagnostic and prognostic factors for patients with AML, as they play an important role in risk stratification algorithms. Hypodiploidy, a rare cytogenetic abnormality resulting in a karyotype with fewer than 46 chromosomes, is a rare finding in AML. It is often characterized by the involvement of chromosomes 5, 7, and/or 17, as well as the structural aberration t(8;21)(q22;q22), which is frequently accompanied by the clonal loss of a sex chromosome. Modal number (MN) has been shown to play a role in prognosis, with lower values associated with poorer survival. While hypodiploidy is frequently discussed within the context of acute lymphoblastic leukemia (ALL), its impact has garnered little relevance within AML studies. In this review, we aim to elucidate the characteristics of hypodiploidy in AML, investigate its prognostic significance, and explore its relationship with monosomal karyotypes, a more favored method of risk stratification.